The Animal and Plant Health Agency (APHA) is an

executive agency of the Department for Environment, Food

& Rural Affairs, and also works on behalf of the Scottish

Government and Welsh Government.

Editor: Susanna Williamson, APHA Bury St Edmunds

Phone: + 44 (0) 1284 724499 Email: Susanna.williamson@apha.gov.uk

GB pig quarterly report

Disease surveillance and emerging threats

Volume 22: Q4 – October to December 2018

Highlights Page

Updates on African Swine Fever in China and Europe 3

Porcine circovirus 3 detection with multisystemic inflammation 6

Leptospirosis in jaundiced growing pigs in autumn-winter months 11

Ampicillin resistance in Actinobacillus pleuropneumoniae 12

Recrudescence of vesicular disease due to SVA in Brazil 13

Contents

Introduction and overview .................................................................................................... 1

New and re-emerging diseases and threats ........................................................................ 3

Unusual diagnoses .............................................................................................................. 6

Changes in disease patterns and risk factors ...................................................................... 9

Horizon scanning ............................................................................................................... 13

References ...................................................................................................................... 134

GB pig quarterly report Disease surveillance and emerging threats

Vol 22: Q4 October - December 2018

1

Introduction and overview

This quarterly report reviews disease trends and disease threats for the fourth quarter of 2018,

October to December. It contains analyses carried out on disease data gathered from APHA,

SRUC Veterinary Services division of Scotland’s Rural College (SRUC) and partner post mortem

providers and intelligence gathered through the Pig Expert Group networks. In addition, links to

other sources of information including reports from other parts of the APHA and Defra agencies are

included. A full explanation of how data is analysed is provided in the Annexe available on

GOV.UK. https://www.gov.uk/government/publications/information-on-data-analysis

Pig disease surveillance dashboard October to December output

Diagnoses made in the fourth quarter of 2018, and for the whole of 2018 through the GB scanning

surveillance network are illustrated in Figures 1a and 1b respectively. These can be interrogated

further using the interactive pig disease surveillance dashboard which was launched in October

2017 and can be accessed from this link: http://apha.defra.gov.uk/vet-

gateway/surveillance/scanning/disease-dashboards.htm

Figure 1: GB scanning surveillance diagnoses

1a 177 diagnoses in Q4-2018 (160 Q4-2017) 1b 843 diagnoses in 2018 (822 in 2017)

Note that diagnoses made in low numbers are not shown and that further diagnoses may be added

if submissions made in 2018 are finalised at a later date.

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Vol 22: Q4 October - December 2018

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Surveillance details for all diagnostic submissions to the GB scanning surveillance network in the

fourth quarter of 2018 and the whole of 2018 from an enhanced pig disease surveillance

dashboard are summarised in Figures 2 and 3 respectively.

Figure 2: Summary surveillance data for 287 diagnostic records in Q4-2018 (272 Q4-2017)

Figure 3: Summary surveillance data for 1,284 diagnostic records in 2018 (1,310 in 2017)

These diagnostic submissions are voluntary and subject to several sources of bias. However it is

interesting to note that the profile of submissions for the fourth quarter and the year are broadly

similar. The most common disease syndromes are, as expected, systemic, enteric and respiratory

which parallels the most common main clinical signs reported which are “diarrhoea & GIT,” “found

dead” and “respiratory”. In line with the trend in recent months described in previous APHA disease

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surveillance reports, APHA non-carcase (postal) submissions remained reduced in Q4-2018

compared to the same period in prior years, and potential reasons were discussed in previous

reports (APHA 2018a). Carcase submission numbers were similar to the same period in the

previous four years but in 2018 comprised nearly 50% of total diagnostic submissions; whereas in

previous years, carcase submissions were usually around one third of total submissions. This may

have an influence on diagnostic rates for certain diseases if they are more likely to be diagnosed in

carcase submissions in which more complete diagnostic investigation is possible. Although the

number of submissions in 2018 is slightly lower than in 2017, the number of diagnoses recorded in

2018 (843) is slightly more than in 2017 (822). The geographical areas where free carcase

collection is offered to post-mortem examination sites within the APHA network were expanded in

2017 (APHA, 2017) and the availability of this service is regularly publicised with some more

uptake occurring.

New and re-emerging diseases and threats

Please refer to the annexe on Gov.UK for more information on the data and analysis.

African swine fever updates

Following the first detection of African swine fever (ASF) in wild boar in Belgium in September 2018 within a forested area of nearly 80 km2 close to the border with France, further infected wild boar continue to be found dead. This is not an area with many commercial pigs: all domestic pigs in the declared zone were culled, and no domestic pigs have been infected in Belgium. Concern about spread into France has prompted intensive culling of wild boar in the border area at risk and fencing. The reported plan is to create a wild boar-free zone with a perimeter fence and further fences at the border. Although wild boar positive for ASF virus (ASFV) continue to be reported in Eastern Europe, there were no large geographical jumps in December 2018 (Figure 4). Romania and Ukraine have reported outbreaks in domestic pigs, with an outbreak in nearby Moldova in December. A qualitative risk assessment for introduction of African swine fever to the UK pig population from European Member States via human-mediated routes was published: https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/770081/asf-qra-november2018.pdf. Given the situation in Belgium and in Eastern Europe, the risk for introduction of ASFV to the UK remains at medium.

Meetings of the Standing Group of Experts on African swine fever in Europe under the ‘The Global

Framework for the Progressive Control of Transboundary Animal Diseases’ (GF-TADs) umbrella

began in 2014 ‘to build up a closer cooperation among countries affected by African Swine Fever

and thereby, address the disease in a more collaborative and harmonised manner across the

Baltic and Eastern Europe sub-region.’ These meetings are attended by ASF-affected countries

with observers from ASF-free countries. The reports and presentations are available on this OIE

webpage and provide valuable insight into ASF in Europe: http://web.oie.int/RR-

Europe/eng/Regprog/en_GF_TADS%20-

%20Standing%20Group%20ASF.htm%20Standing%20Group%20ASF.htm

Updated assessments continue to be published on ASF in Eastern and Central Europe, Belgium and South East Asia: https://www.gov.uk/government/collections/animal-diseases-international-monitoring#outbreak-assessments-2019

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Figure 4: ASF reported in Europe (map as on 31-01-19)

Since

African swine fever was first reported in China in August 2018; it has spread across the country,

and more recently, Mongolia and Vietnam also reported several ASF cases. Several countries

have found ASF virus-infected pork or pork products seized at their borders, including South

Korea, Taiwan and Australia, illustrating the threat of spread posed by undisclosed ASF cases and

human behaviour. ASF-infected pig carcases were found on the beach in Taiwan across the sea

from China. Although Eurasian wild boar are widespread in South East Asia, only China has

reported ASF in one wild boar.

The FAO and Swine Health Information Centre (US) are providing regular updates:

http://www.fao.org/ag/againfo/programmes/en/empres/ASF/Situation_update.html;

https://www.swinehealth.org/global-disease-surveillance-reports/

Communications including videos and advice to pig keepers and veterinarians, hauliers and hunters are being actively publicised and disseminated to raise awareness within the country and amongst those travelling to and from the UK: AHDB Pork ASF information https://www2.gov.scot/Resource/0054/00542877.pdf https://www2.gov.scot/Resource/0054/00542878.pdf

Images of the clinical signs and pathology of ASF are available, suspect cases should be reported

promptly and an official veterinary investigation follows: https://www.gov.uk/guidance/african-

swine-fever and http://apha.defra.gov.uk/documents/surveillance/diseases/african-swine-fever-

images.pdf

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Porcine epidemic diarrhoea surveillance

Since the emergence of virulent porcine epidemic diarrhoea (PED) from mid-2013 in the

USA and elsewhere, the virulent PED virus strain has only been reported in Ukraine on the

European continent (Dastjerdi and others, 2015). However, reportedly less virulent strains

(known as INDEL strains) have been reported in pigs on several continents, including

countries in Europe. These INDEL strains have both an insertion and a deletion in the

PEDV S gene and the first INDEL strain, named OH851, was described in the US in 2014

(Wang and others, 2014). PED due to any strain remains notifiable in England and

Scotland and suspicion of disease, or confirmation of infection, must be reported (Defra,

2015; Scottish Government, 2016). The last diagnosis of PED recorded in the GB

diagnostic database (VIDA) was in 2002 on a farm in England. No suspect incidents of

porcine epidemic diarrhoea (PED) were reported in England or Scotland during Q4-2018.

Enhanced surveillance for PED continues and diagnostic submissions from cases of

diarrhoea in pigs (non-suspect) submitted to APHA are routinely tested for PEDV on a

weekly basis. None have tested positive for PEDV in over 800 diagnostic submissions

tested under AHDB Pork funding between June 2013 and December 2018. Further

information on PEDV is available on this link: https://pork.ahdb.org.uk/health-

welfare/health/emerging-diseases/pedv.

Official investigation rules out swine fevers

Clinical signs including coughing, lethargy, blue ears, pyrexia and some wasting affected

around a third of finisher pigs on an indoor unit. Mortality increased with 50 deaths and a

further 30 pigs requiring euthanasia within a week. Six of those dying had haemorrhagic

renal and skin lesions and enlarged lymph nodes. These findings prompted the private

veterinarian to notify the case to the APHA as suspect swine fever and an official

veterinary enquiry took place. Swine fevers could not be ruled out on clinical grounds so

restrictions were placed on the unit and samples were collected which tested negative for

African and classical swine fevers, allowing restrictions to be lifted.

As the swine fevers had been ruled out, it was suspected that the haemorrhagic disease

was porcine dermatitis and nephropathy syndrome (PDNS) relating to porcine circovirus 2-

associated disease (PCVD). However this could not be confirmed as none of the pigs

subsequently submitted for diagnostic investigation had haemorrhagic lesions; they

showed lymph node enlargement and severe pneumonias (Figure 5) with marked, dark-

purple cranioventral consolidation. The complex pneumonias had PRRS

(immunohistochemistry and PCR-positive), bacterial (Pasteurella multocida) and

mycoplasmal (Mycoplasma hyopneumoniae and M. hyorhinis detected) involvement and

there was no evidence of PCV2-associated disease or PDNS in these pigs. The pigs were

reported to be vaccinated against Mycoplasma hyopneumoniae, PCV2 and PRRS virus,

although the private veterinarian had concerns that some pigs may not have been

vaccinated correctly.

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Figure 5: Pneumonia in finisher pig associated with PRRS, Pasteurella multocida and

mycoplasmal infections

Unusual diagnoses or presentations

Porcine circovirus 3 detection with multisystemic inflammation

Investigations were described in the last quarterly report (APHA 2018b) in a herd affected

with congenital tremor (CT) in gilt litters associated with atypical porcine pestivirus (APPV)

infection, along with an unusual concurrent increase, in different litters, of stillborn piglets,

some with limb deformities (Figure 6). Widespread multisystemic inflammation, consisting

primarily of lymphoplasmacytic infiltrates, was detected involving skeletal muscle, CNS

and other tissues of several stillborn piglets examined. The distribution and nature of these

infiltrates was unusual and suggested a chronic systemic antigenic stimulus, most likely

reflecting an in utero viral infection. Immunohistochemistry for PRRSV and PCV2 did not

detect these viruses in association with histopathological lesions. APPV was detected in

CT-affected pigs from the farm, but was not detected in stillborn piglets with these lesions

and therefore virus microarray was undertaken (APHA, 2018c). In CT-affected APPV-

positive piglets this detected only APPV, while in stillborn piglets with multisystemic

inflammation, porcine circovirus type 3 was detected, and subsequently confirmed by RT-

PCR with low Ct values suggesting high viral loads.

The significance of the PCV3 in relation to clinical disease is uncertain and further analysis

is in progress although this clinical presentation has subsided on the farm. PCV3 is distinct

from PCV2 and has been reported in pigs since 2016 in a growing number of countries

globally, including the US, China, Poland, Italy, Spain and the UK (Palinski and others,

2016; Collins and others, 2017). It is reported to have been detected in samples from

healthy pigs and in samples from pigs with a variety of disease presentations, including

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PDNS-like disease. A recent publication reported experimental infection of weaned pigs

with PCV3 (Jiang and others, 2019). The disease induced in some respects resembled

PDNS. No zoonotic concern is reported. Information from an increasing number of

countries indicates that PCV3 is widespread in pigs globally and publications suggest that

this virus, although newly discovered in pigs, has been present in the pig population for a

number of years.

There are reports in the literature of PCV3 detection with high viral loads in stillborn and

aborted piglets (Palinski and others, 2016; Faccini and others, 2017) and in semen (Ku

and others, 2017; Li and others, 2018) indicating that vertical transmission is potentially

possible; however histopathological findings in PCV3-positive foetuses or stillbirths were

not reported. Multisystemic inflammation has been described in growing pigs which were

PCV3-positive (Phan and others, 2016).

APHA scanning surveillance are interested to hear of any similar findings; this incident

occurred in a single herd during autumn 2018. The case was presented for discussion at

the December European Pathosurveillance Network meeting and an abstract has been

submitted for possible presentation of the case at the 2019 European Symposium for

Porcine Health Management in Utrecht.

PCV2-associated disease with unusual cerebellar lesions

A grower pig submitted to APHA Thirsk VI Centre to investigate nervous and respiratory

signs in growers on an indoor breeder-finisher unit was found to have porcine circovirus 2-

associated disease (PCVD) with unusual cerebellar lesions. Twelve growers in a group of

350 had died, and others were coughing. Post-mortem findings included wasting, oedema

Figure 6: Arthrogryposis in

stillborn piglet

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of sub-cutaneous tissues and serous atrophy of epicardial fat, gastric ulceration,

pneumonia, generalised lymphadenopathy and a reddened cerebellum (Figure 7).

Histological examination revealed a non-suppurative myocarditis, interstitial pneumonia,

granulomatous lymphadenitis and acute necrotising rhombencephalitis (encephalitis

primarily affecting the cerebellum and hindbrain). Lymphoid and other lesions were

consistent with PCVD and this was confirmed with all the tissues staining positive for

PCV2 antigen by immuno-histochemistry. Influenza A RNA was also detected in a pool of

tonsil, trachea and lung from this pig and active swine influenza was likely to be involved in

the more widespread coughing reported on the farm while PRRS was also diagnosed in an

earlier submission from this farm and may also have been contributing to the wider

disease. Cerebellar lesions associated with PCV2 are an unusual finding in PCVD, but

are reported in the literature (Seeliger and others, 2007) and have been detected in APHA

PCVD cases on just a few occasions since disease emerged in GB from 1999. The pigs

were vaccinated at weaning for PCV2 and enzootic pneumonia. The occurrence of PCVD

in a small proportion of vaccinated pigs is being investigated to determine whether there

was any issue with vaccine compliance and material from this case will be genotyped at a

future date. This case serves as a reminder of a less common differential for neurological

disease in growers.

Figure 7: Reddened cerebellum in a post-weaned pig diagnosed with PCV2-associated

rhombencephalitis

Mycotic abortion due to Aspergillus species infection

Several abortions approximately four weeks pre-term occurred in a group of outdoor gilts

which were otherwise healthy. One litter which had not been scavenged was submitted for

diagnostic investigation. The placenta was thickened and roughened with fibrinopurulent-

like exudate (Figure 8a) and there were multiple, cream-coloured and slightly raised

circular lesions on the foetal skin with overlying exudate (Figure 8b). These raised

suspicion of a fungal or bacterial cause. Histopathology showed typical mycotic lesions in

both the placenta and skin. Fungal hyphae were identified using special staining (PAS)

whilst culture yielded Aspergillus species from foetal stomach contents. Both methods

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confirmed a diagnosis of mycotic abortion. Risk factors for mycotic abortion relate to

exposure of the pregnant dam to fungal spores in the environment, usually from bedding,

bedding stores or feed. The farmer mentioned that the affected batch of gilts behaved

oddly when placed in the paddock four weeks prior to the abortions. For the first three

days they did not enter their huts, preferring to sleep at the paddock edge where there

were overhanging crab apple trees. Access to mouldy fallen apples is a possible source in

this case. There was no obvious issue with feed and the straw in use was regarded as

being of excellent quality.

Changes in disease patterns and risk factors

Please refer to the annexe on Gov.UK for more information on the data and analysis.

Swine dysentery diagnosed in East Anglia

Swine dysentery was diagnosed in the East Anglian region in November 2018. This adds

to cases of swine dysentery detected in several regions during 2018 in England with

diagnoses made in North, South and West Yorkshire, Lancashire, Somerset,

Worcestershire and Devon, and one in Wales as described in the Q3-2018 surveillance

report (APHA 2018b). In this East Anglian case, Brachyspira hyodysenteriae was detected

by PCR and/or culture in faeces from seven- and nine-week-old pigs submitted to

investigate diarrhoea. The older pigs had gross evidence of colitis and Brachyspira

pilosicoli was also detected in some pigs. The B. hyodysenteriae isolate underwent

antimicrobial sensitivity testing under surveillance funding and the Minimum Inhibitory

Concentration (MIC) results suggested that the isolate was sensitive to all the

Figure 8: Placentitis (8a) and foetal skin

lesions (8b) due fungal infection

8a

9a

8b

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antimicrobials tested and the pigs were reported to have responded well to lincomycin

treatment. This wide in vitro sensitivity is uncommon in recent years in B. hyodysenteriae

isolates, with many showing resistance to tylosin, and sometimes other antimicrobials. The

last case from which Brachyspira hyodysenteriae was isolated in the East Anglian region

was in March 2017 when an atypical isolate was detected causing diarrhoea in indoor

growing pigs and described in the Q1, 2017 quarterly report (APHA, 2017). Whole genome

sequencing has shown that the isolate involved is not similar to the March 2017 isolate, or

to others analysed by APHA from outbreaks elsewhere in the country and the source of

infection has not been determined.

The development of resistance in B. hyodysenteriae to antimicrobials commonly used in

the control of swine dysentery is a recognised risk, particularly in situations where

medication is used long-term. Control of swine dysentery using alternative interventions

(all-in, all-out management systems; cleaning and disinfection; rodent control, and partial

and total depopulation leading to elimination) is vital to prevent the development of wider

antimicrobial resistance.

Figure 9: GB incidents of swine dysentery in pigs as % diagnosable submissions

The slight upward trend in the diagnostic rate for swine dysentery (Figure 9) was

highlighted in the Veterinary Record December 2018 surveillance report and an

information sheet for pig producers and their vets was disseminated:

http://apha.defra.gov.uk/documents/surveillance/diseases/swine-dysentery.pdf

Although swine dysentery is described as a mucohaemorrhagic colitis, blood is not always

evident. Prompt diagnosis by submission of faeces or pigs for culture and PCR is

important so that suitable control measures are quickly implemented to help limit the

impact of disease and spread of infection. Swine dysentery tends to cause most obvious

clinical signs in growers, finishers and younger breeding stock, with low to moderate

mortality. Further guidance on sampling for diagnosis is available on this link:

http://ahvla.defra.gov.uk/documents/surveillance/sub-handbook.pdf The severity of

disease is affected by age, immunity, diet, concurrent disease and the strain of B.

hyodysenteriae. Further information on swine dysentery and its control is provided through

these links: https://pork.ahdb.org.uk/health-welfare/health/swine-dysentery/;

http://www.nadis.org.uk/disease-a-z/pigs/swine-dysentery/; https://pork.ahdb.org.uk/health-

welfare/health/significant-diseases-charter

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Leptospirosis in jaundiced growing pigs in autumn-winter months

An outbreak of leptospirosis was diagnosed in December following the submission of

jaundiced, growing pigs to the APHA partner post-mortem provider, the University of

Surrey. A large rat population was noted in the pig buildings. Cumulative mortality since

the pigs’ arrival as weaners had reached 20 per cent. The outbreak prompted a farm visit

by an APHA VIO to investigate whether there was involvement of coal tar toxicity which

can also cause jaundice and would represent a potential food safety issue. Acute

leptospirosis was diagnosed in the submitted pigs following PCR testing of renal tissue.

Concurrent infections were also identified in several pigs, contributing to the severity of

disease on farm. These included salmonellosis due to monophasic Salmonella

Typhimurium-like variant 4,12:i:- phage type 193 and Brachyspira pilosicoli in diarrhoeic

pigs, and Streptococcus suis serotype 2 septicaemia. Serology is useful in confirmed

cases of leptospirosis to identify the infecting serovar, as the PCR is generic for

pathogenic leptospires. Involvement of a rodent-associated serovar, such as L.

Icterohaemorrhagiae, was strongly suspected in this incident. Advice was given at the visit

regarding avoiding zoonotic infection and controlling disease in the pigs, in particular,

recommending rodent control and improved hygiene and management. The attending

veterinarian subsequently reported that pigs had responded to treatment and mortality had

stopped.

Table 1 summarises APHA leptospirosis diagnoses in growing pigs from 2011 to 2018; in

all cases, jaundice was a consistent finding. The main differentials for jaundice in growing

pigs include PCVD-associated hepatitis, coal tar toxicity and Mycoplasma suis.

Table 1: Non-reproductive diagnoses of leptospirosis by APHA in pigs 2011-2018

Month Age Clinical signs reported

November Postwean 5 weeks

Jaundice, lethargy, anaemia and death

October Prewean 4 weeks

Jaundice, slight diarrhoea, one death

September Postwean 6 weeks

Jaundice, lethargy, weight loss, 3 affected of 85. Good response to penicillin.

September Preweaned Jaundice and lethargy

August Preweaned 1-4 weeks

Jaundice, weight loss, fading from one-week-old, 30-40 piglets affected in batch of 1000+

December Postwean 6-8 weeks

Jaundice, lethargy, shaking, death within 12 hours. Mortality 20% - concurrent diseases

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There is a tendency illustrated in Figure 10 for diagnoses of leptospirosis (causing either

reproductive and non-reproductive disease) to be made in the autumn/winter months

possibly reflecting greater rodent (and other wild mammal) incursion to pig accommodation

and feed as it becomes colder and food sources become more scarce, and also wetter

conditions influencing leptospire spread. Confirmed leptospirosis cases in humans were

reviewed in the 2017 UK Zoonoses Report (PHE, 2017). Interestingly, this also reported

that symptom onset was highest in the autumn months for leptospirosis cases acquired by

people in the UK.

Figure 10: Seasonality of APHA reproductive and non-reproductive leptospirosis diagnoses 2011-2018

Ampicillin resistance in Actinobacillus pleuropneumoniae

Respiratory disease involving Actinobacillus pleuropneumoniae (APP) was diagnosed as

the cause of sudden death of a finisher pig. The APP isolated showed ampicillin resistance

on disc diffusion testing, which was confirmed by further work under the ‘Monitoring of

Antimicrobial Resistance in Bacteria from Animals and their Environment Project’ within

APHA. Whole genome sequencing showed that this resistance was linked to the presence

of the blaROB-1 gene, which is commonly present on transferable plasmids and can thus

be transferred to other bacteria, significantly to other Gram-negative respiratory

pathogens, such as Pasteurella multocida and Haemophilus parasuis. Ampicillin (beta-

lactam) resistance in APP is occasionally detected by APHA in isolates from clinical cases

(VMD, 2018); none were detected in 2017, and only this isolate in 2018. A past study by

Bosse and others (2017) reported ampicillin resistance in 20% of 96 UK isolates

examined, in all cases associated with the presence of the blaROB-1 gene. This

resistance is of concern as penicillin/penicillin derivatives are the drugs of choice for the

control of APP outbreaks. Increasing beta-lactam resistance in APP has been reported in

some other countries for example, ampicillin resistance increased from 11% of isolates in

1994 to 80% in 2009 in Italy (Vanni et al, 2012). Improving pig flow and ventilation and

0

0.5

1

1.5

2

2.5

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Jan Feb March April May June July Aug Sept Oct Nov Dec

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avoiding other predisposing factors such as viral disease and stresses are important in

controlling disease due to APP in infected herds and to reduce reliance on antimicrobial

treatment. There is an ongoing review of results from antimicrobial resistance surveillance

on porcine bacterial pathogens isolated at APHA.

Horizon scanning

Recrudescence of vesicular disease due to Senecavirus A in Brazil

The US Swine Health Information Centre (SHIC) described recent re-emergence of

vesicular disease associated with Senecavirus A (SVA) clinically indistinguishable from

notifiable vesicular diseases in pigs in Brazil (SHIC, 2019). Multiple pig herds in Brazil

were affected in 2014-15 (Vanucci and others, 2015) as were herds in the US from July

2015 and an information note was provided on the vet gateway at that time:

http://apha.defra.gov.uk/documents/surveillance/diseases/seneca-valley-virus.pdf.

Lesions, particularly those on the feet, appear more severe and are taking longer to fully

resolve. Whether these new outbreaks in Brazil reflect a change in the virus, or a change

in herd immunity, is being investigated.

An updated version of the National Pig Association import protocol has recently been

published and includes requirements relating to Senecavirus A and several other non-

statutory pathogens of pigs: http://www.npa-

uk.org.uk/hres/NPA%20imports%20protocol%20Feb%202019. The vesicular

manifestation of SVA infection is of concern because the lesions closely resemble those

caused by notifiable vesicular diseases, in particular foot and mouth disease. No vesicular

disease outbreak report cases in pigs have occurred in the UK in recent years to suggest

that SVA is present or emerging. However, pig keepers and veterinarians attending pigs

are reminded that any vesicular lesions seen in pigs must immediately be reported to the

APHA as suspect notifiable disease for investigation as described here:

https://www.gov.uk/guidance/foot-and-mouth-disease. The Pirbright Institute has a

diagnostic PCR test for SVA for use on material from lesions; however this would be

permitted only after investigation for notifiable causes of vesicular disease has ruled them

out.

Metagenomic analysis in periweaning failure-to-thrive syndrome

A reminder of features of periweaning failure-to-thrive syndrome (PFTS) was included in

the Q3-2018 report (APHA 2018e) PFTS affects pigs two to three weeks after weaning

resulting in anorexia, lethargy and progressive debilitation. It has been reported in pigs

mainly in North America, and also in Spain, but not in the UK, and the aetiology is not

clear. A publication by Franzo and others (2018) reports investigation into the potential role

of viral agents in PFTS-affected compared with healthy animals, using a metagenomic

approach. Several DNA viruses, including PCV-3 were more abundant in pigs with PFTS.

These preliminary results are not conclusive regarding the potential role of the identified

GB pig quarterly report Disease surveillance and emerging threats

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viruses in relation to the clinical syndrome of PFTS, however they provide a basis for

further studies.

References APHA (2018a). Diagnostic submission trends. Vol 22: Q1 page 3

https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_

data/file/714048/pub-survrep-p0118.pdf

APHA (2018b). Congenital tremor in a herd with concurrent deformities. Vol 22: Q3 page 5

https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_

data/file/761794/pub-servrep-p0718.pdf

APHA (2018c). Virus discovery service. http://apha.defra.gov.uk/apha-

scientific/services/virus-discovery-service/

APHA (2018d). Swine dysentery diagnoses in several regions of Great Britain. Vol 22: Q3

page 11

https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_

data/file/761794/pub-servrep-p0718.pdf

APHA (2018e). Periweaning Failure to Thrive Syndrome – a reminder. Vol 22: Q3 page 15

https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_

data/file/761794/pub-servrep-p0718.pdf

Bossé JT, Li Y, Rogers J, Fernandez Crespo R, Li Y, Chaudhuri RR, Holden MTG,

Maskell DJ, Tucker AW, Wren BW, Rycroft AN, and Langford PR on behalf of the

BRaDP1T Consortium (2017). Whole Genome Sequencing for Surveillance of

Antimicrobial Resistance in Actinobacillus pleuropneumoniae. Front. Microbiol. 8:311. doi:

10.3389/fmicb.2017.00311

https://www.frontiersin.org/articles/10.3389/fmicb.2017.00311/full

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